Method of cutting roofing or like sheets



INVENTOR f mmef ATTORNEY Sept. 29, 1936. E. E. VENRICK METHOD OF CUTTING ROOFING OR LIKE SHEETS Filed April 20, 1935 491.

Patented Sept. 29, 1936 UNITED STATES PATENT oFFice Emmett E. Venrik, Kansas City, Mo., assignor to American Asphalt Roof Corporation, Kansas City, Mo., a corporation of Missouri Application April 20, 1933, Serial No. 666,992

2. Claims. (01. 91-68) My invention relates to a method of cutting roofing or like sheets of the type composed of laminations of saturated felt or other fibrous material asphalt or other waterproofing material on opposite faces of the base lamination and a top lamination of mineral particles, to form plain roofing or other covering strips, shingle strips or individual shingles.

Sheets of the type to which my invention relates are usually delivered from the mill in rows to be slit or die cut longitudinally and/or transversely of the sheet to form individual plain covering strips, shingle strips or individual shingles of desired shape and size.

It is a common practice to cut the sheets from the under or thinly waterproofed side to approximately the coating or minera. particle lamination and then break the latter to avoid rapid dulling of the knives or dies which would otherwise result from the cutting contact of the cutting edges with the mineral particles. Such operation not only leaves a ragged edge on the portion of the covering strip exposed to view that detracts from appearance of the covering body, but the edges of the severed portions of the base and waterproofing laminations are left exposed to sun heat and weather so that the interior laminations deteriorate in quality, due to evaporation of saturant in the base sheet and entrance of moisture into the base sheet, and. the strip or shinglewill warp or become distorted as a result of uneven expansion and contraction.

It is the principal object of my invention to provide a. method of cutting sheets of this character whereby formation of the rawedges on the covering strip and exposure of the edges of interior laminations may be averted.

In the accompanying drawing illustrating practice of and results of practice of my method of cutting material of. the character described:

Fig. l is a. cross section of a covering-strip in process of severance according to my improved method.

2 is a similar View showing a sheet in process of being die out according to my method to form shingle tabs.

Fig. 3 is a perspective view of part of a shingle strip out according to my method, particularly illustrating protected edges of the strip and shingle tabs.

Referring more in detail to the drawing:

- I designates a sheet of roofing or like covering material of conventional composition in that it is composedof a base ply or lamination 2, formed of wool felt or the like, saturated with asphalt or sheet severed by the knife bar.

other waterproofing material. 3 designates the bottom ply of the sheet, i. e., the face of the sheet that contacts a roof or wall member to which the covering is applied and which is usually flowed onto the base sheet and scraped to provide a c lamination of desired thickness.

4 designates a waterproofing ply or lamination on the upper surface of the base sheet, composed of the same material as the under lamination s but of greater thickness because of its protective 1th requirements. 5 designates the coating lamination composed of mineral particles such as ground granite, crushed slate, or the like.

In cutting a sheet of this character according to my method, a knife bar 6, having a severing l5 edge 5 and an inclined pressing face 8 extending from the severing edge at one or each side of the knife bar, is forced into the sheet from the side thereof carrying the coating surface to sever the sheet and translate edge portions of the waterproofing and coating laminations over the severed edge of the base lamination. I prefer to employ a knife bar or die having a slightly dulled edge and roughened pressing face or faces in order to avoid clean cutting of the material and 5 smooth passage of the bar or die therethrough, the dulled edge and roughened side face serving better to displace and translate the material laterally with the severed edges to effect the desired sealing.

The waterproofing lamination of the sheet being plastic and the mineral particles, constituting the coating lamination, being partially embedded in the outer surface of the waterproofing lamination as a result of application thereto while 35 the waterproofing material is hot and relatively fluid, pressure of the flat inclined pressing face 8 of the cutting blade will tend to bend the edge portion of the waterproofing .lamination downwardly over the edge of the base lamina- 40 tion, displacement of the material by knife bar forcing the plastic material of the waterproofing lamination into the exposed edge of the fibrous body to seal said edge, and the mineral particles of the displaced edge portions of the coating 45 lamination being pressed into the plastic mate- .rial to provide a coating for the severed edges similar to the coating'onthe top surface of the strip.

When a sheet of this character is, to be severed 50 merely for forming plain strips, or in cutting a plurality of shingles from a strip, the knife bar may be inclined at each side of the cutting edge to seal the edges of the respective portions of the When the method is employed for forming shingle strips by cutting slots 9, (Fig. 3), and intervening tabs ill in and on one edge of a plain strip of said material, a die, represented by the spaced knife bars ll having single inclined faces l2 at their outer edges and straight innner sides I3, is substituted for the single double faced knife bar 6, heretofore described, in order to permit the cut-outs it to pass upwardly through the i die while the die translates the outer laminations ot the sheet at the edges of the tab portions of the strip and at the ends of the cut-out slots; detail construction of the cutting member being im material except that it shall have an inclined face extending from at least one side of the 7 cutting edge for the purpose of translation of the waterproofing and coating laminations of the sheet as severance of the sheet or cut-out of the tab-forming slots progresses.

It is apparent that by cutting the sheet in accordance with my method, I obviate formation or rough edges on the exposed surface of the covering sheet or body and seal the exposed edges thereof to avoid deterioration \of material and warping and bending of the sheet when exformed to 'a great extent by displacement as distinguished from severance of the material and that advantage is taken of such displacement or translation of material to efiect the desirable sealing of the severed portions of the sheet.,

It is further apparent that such covering ccinposed of sheets or shingles severed according to my invention will present a sightly appearance because of the angular, clean cut edges of the shingle members or tabs, and that the smooth out angular edges will better deflect water from. the exposed edges of the shingles or tabs.

What I claim and desire to secure by Letters Patent is: 1. The method of cutting a sheet of the type including a base lamination of saturated fibrous material, a waterproofing lamination of plastic material and an upper coating lamination of mineral particles, including cutting successively through the laminations from the coated side of the sheet, translating edge portions of the waterproofing lamination completely over the severed edge of the base lamination, and translating the mineral particles over the water-proofing lamination by pressure thereon at the time and place of cutting, and translation of said water proofing lamination whereby the cut edges have the same appearance as the surface of the sheet. 2. The method of cutting a' sheet of the type including a base lamination of saturated fibrous material, a waterproofing lamination of plastic material and an upper coating lamination of mineral particles, including cutting successively through the laminations from the coated side of the sheet, translating an edge of the waterproofing larnination completely over and into the severed edges or the base portion, and translating the mineral particles over the translated surface of the water proofing lamination by pressure thereon in a plane inclined from the line of severance at the. time and place of cutting and translation of said water proofing lamination.

E E. VENRICK. 

